Video: Dirty-bomb fears

WASHINGTON — The port of Long Beach, Calif. — among the busiest in the nation — is a key line of homeland defense. Some 4.5 million shipping containers pass through each year.

Big radiation portal monitors scan some — but not all — containers for traces of nuclear or radiological material as they leave the port. But, four-and-a-half years after 9/11, Senate investigators say only 39 percent of all containers entering the U.S. are screened for nuclear material. Many ports, including the third-largest, Miami, still have only handheld detection devices of little value.

“We still have massive blind spots in our ability to prevent nuclear material from being smuggled into this country,” says Sen. Norm Coleman, R-Minn.

Coleman says the Department of Homeland Security still is not moving nearly fast enough.

A report by the Government Accountability Office concludes DHS is two years behind schedule in installing radiation monitors in ports and not likely to have them all done, even by 2009.

DHS has made more progress installing detection equipment at the borders, but there investigators found another hole in the system. Coleman tells NBC News that undercover GAO investigators were able to bring enough radioactive material into the U.S. to make two dirty bombs — penetrating both the northern and southern borders. Monitors detected the radiological material, but undercover agents produced fake papers and got the material in.

“They were able to use counterfeit documents they got off a basic program on a computer,” Coleman says.